1
|
Niu X, Wang H, Zhao L, Lian P, Bai Y, Li J, Qiao J. All-trans retinoic acid increases the pathogenicity of the H9N2 influenza virus in mice. Virol J 2022; 19:113. [PMID: 35764970 PMCID: PMC9238145 DOI: 10.1186/s12985-022-01809-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 05/08/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The H9N2 virus can infect not only birds but also humans. The pathogenicity of H9N2 virus infection is determined by an excessive immune response in the lung. All-trans retinoic acid (ATRA), the active metabolite of vitamin A, plays an important regulatory role and has been widely used in the clinical practice. This study was aimed to investigate whether ATRA could regulate the immune response to H9N2 virus infection in the lungs of mice, thereby reducing the pathogenicity of the H9N2 virus in mice. METHODS Mice were infected intranasally with H9N2 virus, and injected intraperitoneally with 0.2 mL of ATRA at low (1 mg/kg), medium (5 or 10 mg/kg), or high therapeutic dose (20 mg/kg), and toxic dose (40, 60, or 80 mg/kg), once per day for 10 days. Clinical signs, survival rates, and lung gross pathology were compared between the ATRA-treated H9N2-infected group, the ATRA group, and the H9N2-infected group, to investigate the effect of different doses of ATRA on the pathogenicity of H9N2 virus. Additionally, the viral load and cytokine concentration of lungs were measured at 3, 5, 7, and 9 days after infection, to investigate the potential mechanism of ATRA in affecting the pathogenicity of the H9N2 virus. Expression levels of cellular retinoic acid-binding protein 1 (CRABP1), cellular retinoic acid-binding protein 2 (CRABP2), and Retinoic acid-inducible gene-I (RIG-I) were detected using Western blotting. RESULTS The ATRA-treated H9N2-infected mice showed more severe clinical signs compared with the H9N2-infected group. The medium and high therapeutic doses of ATRA reduced the survival rates, aggravated lung tissue damage, decreased the expression of interferon beta (IFN-β), and increased the concentrations of interleukin-1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), and C-C motif chemokine ligand 2 (CCL2) in the lungs of the H9N2-infected mice. At the same time, the expression patterns of CRABP1, CRABP2, and RIG-I were changed in mice infected by H9N2 and treated with different concentrations of ATRA. CONCLUSIONS Our findings suggest that the therapeutic dose of ATRA can increase the pathogenicity of the H9N2 virus. Therefore, the consequences of those infected by influenza virus would be more severe after ATRA treatment.
Collapse
Affiliation(s)
- Xiaofei Niu
- Department of Pathophysiology, College of Veterinary Medicine, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China.,Department of Veterinary Medicine, College of Life Sciences and Food Engineering, Hebei University of Engineering, No. 19 Taiji Road, Economic and Technological Development Zone, Handan, 056038, People's Republic of China
| | - Hongyan Wang
- Department of Veterinary Medicine, College of Life Sciences and Food Engineering, Hebei University of Engineering, No. 19 Taiji Road, Economic and Technological Development Zone, Handan, 056038, People's Republic of China
| | - Lihong Zhao
- Department of Pathophysiology, College of Veterinary Medicine, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Pengjing Lian
- Department of Pathophysiology, College of Veterinary Medicine, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Yu Bai
- Department of Pathophysiology, College of Veterinary Medicine, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Jingyun Li
- Department of Pathophysiology, College of Veterinary Medicine, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Jian Qiao
- Department of Pathophysiology, College of Veterinary Medicine, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China.
| |
Collapse
|
2
|
Mosad SM, El-Gohary FA, Ali HS, El-Sharkawy H, Elmahallawy EK. Pathological and Molecular Characterization of H5 Avian Influenza Virus in Poultry Flocks from Egypt over a Ten-Year Period (2009-2019). Animals (Basel) 2020; 10:ani10061010. [PMID: 32527004 PMCID: PMC7341251 DOI: 10.3390/ani10061010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/02/2020] [Accepted: 06/04/2020] [Indexed: 01/10/2023] Open
Abstract
Simple Summary Avian influenza virus (H5) remains one of the challenging zoonotic viruses in Egypt. Our study investigated the occurrence of this virus among chickens from Dakhalia governorate, Egypt over ten years through histopathological examination and molecular characterization of the virus. The molecular characterization was followed by sequencing and phylogenetic analysis of the positive samples. Importantly, we have reported several interesting pathological changes and high occurrence of the H5 avian influenza virus, the phylogenetic analysis revealed that positive samples were aligned with several Egyptian sub clades. Clearly, our study concludes the widespread of the virus among poultry flocks in Egypt and suggests further future research aims to develop an efficient surveillance program with investigation into the effectiveness of the implemented control measures for controlling this disease of public health concern. Abstract Avian influenza virus (AIV) remains one of the enzootic zoonotic diseases that challenges the poultry industry in Egypt. In the present study, a total of 500 tissue samples were collected from 100 chicken farms (broilers and layers) suspected to be infected with AIV through the period from 2009 to 2019 from Dakahlia governorate, Egypt. These samples were pooled in 100 working samples and screened for AIV then the positive samples were subjected to histopathological examination combined with real time-polymerase chain reaction (RRT-PCR). RRT-PCR positive samples were also subjected to conventional reverse transcriptase-polymerase chain reaction (RT-PCR) for detection of H5 AIV and some of these resulting positive samples were sequenced for detection of the molecular nature of the studied virus. Interestingly, the histopathological examination revealed necrotic liver with leukocytic infiltration with degenerative changes with necrotic pancreatitis, edema, and intense lymphoid depletion of splenic tissue and hyperplastic tracheal epithelium. Likewise, edema and congested sub mucosal blood vessels and intense bronchial necrosis with hyalinized wall vascular wall and heterophils infiltration were reported. Pneumonic areas with intense leukocytic aggregation mainly and vasculitis of the pulmonary blood vessels were also detected in lung. Collectively, these significant pathological changes in examined tissues cohered with AIV infection. Regarding the molecular characterization, 66 samples were positive for AIV by RRT-PCR and 52 of them were positive for H5 AIV by RT-PCR. The phylogenetic analysis revealed that the H5 viruses identified in this study were aligned with other Egyptian H5N1 AIVs in the Egyptian sub clade 2.2.1, while some of the identified strains were aligned with other Egyptian H5N8 strains in the new Egyptian sub clade 2.3.4.4. Taken together, our present findings emphasize the wide spread of AIV in Egypt and the importance of developing an efficient surveillance and periodical screening program for controlling such disease of public health concern.
Collapse
Affiliation(s)
- Samah Mosad Mosad
- Department of Virology, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt;
| | - Fatma A. El-Gohary
- Department of Hygiene and Zoonoses, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt;
| | - Hanaa Said Ali
- Department of Pathology, Animal Health Research Institute, Mansoura Branch, Mansoura 35516, Egypt;
| | - Hanem El-Sharkawy
- Department of Poultry and Rabbit Diseases, Faculty of Veterinary Medicine, Kafrelsheikh University, Kafrelsheikh 33511, Egypt;
| | - Ehab Kotb Elmahallawy
- Department of Biomedical Sciences, University of León, 24071 León, Spain
- Department of Zoonotic Diseases, Faculty of Veterinary Medicine, Sohag University, Sohag 82524, Egypt
- Correspondence:
| |
Collapse
|
3
|
Dong Z, Ya X, Wang D, Liu C, Shen Q, Xia Y. Genetic Characterization of a Novel Reassortant H5N6 Avian Influenza Virus Identified from a 10-Year-Old Girl. Jpn J Infect Dis 2020; 73:36-43. [DOI: 10.7883/yoken.jjid.2019.101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Zefeng Dong
- Suzhou Center for Disease Prevention and Control
| | - Xuerong Ya
- Suzhou Center for Disease Prevention and Control
| | - Di Wang
- Suzhou Center for Disease Prevention and Control
| | - Cheng Liu
- Suzhou Center for Disease Prevention and Control
| | - Qiang Shen
- Suzhou Center for Disease Prevention and Control
| | - Yu Xia
- Suzhou Center for Disease Prevention and Control
| |
Collapse
|
4
|
Guan M, Hall JS, Zhang X, Dusek RJ, Olivier AK, Liu L, Li L, Krauss S, Danner A, Li T, Rutvisuttinunt W, Lin X, Hallgrimsson GT, Ragnarsdottir SB, Vignisson SR, TeSlaa J, Nashold SW, Jarman R, Wan XF. Aerosol Transmission of Gull-Origin Iceland Subtype H10N7 Influenza A Virus in Ferrets. J Virol 2019; 93:e00282-19. [PMID: 30996092 PMCID: PMC6580963 DOI: 10.1128/jvi.00282-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 04/09/2019] [Indexed: 01/02/2023] Open
Abstract
Subtype H10 influenza A viruses (IAVs) have been recovered from domestic poultry and various aquatic bird species, and sporadic transmission of these IAVs from avian species to mammals (i.e., human, seal, and mink) are well documented. In 2015, we isolated four H10N7 viruses from gulls in Iceland. Genomic analyses showed four gene segments in the viruses were genetically associated with H10 IAVs that caused influenza outbreaks and deaths among European seals in 2014. Antigenic characterization suggested minimal antigenic variation among these H10N7 isolates and other archived H10 viruses recovered from human, seal, mink, and various avian species in Asia, Europe, and North America. Glycan binding preference analyses suggested that, similar to other avian-origin H10 IAVs, these gull-origin H10N7 IAVs bound to both avian-like alpha 2,3-linked sialic acids and human-like alpha 2,6-linked sialic acids. However, when the gull-origin viruses were compared with another Eurasian avian-origin H10N8 IAV, which caused human infections, the gull-origin virus showed significantly higher binding affinity to human-like glycan receptors. Results from a ferret experiment demonstrated that a gull-origin H10N7 IAV replicated well in turbinate, trachea, and lung, but replication was most efficient in turbinate and trachea. This gull-origin H10N7 virus can be transmitted between ferrets through the direct contact and aerosol routes, without prior adaptation. Gulls share their habitat with other birds and mammals and have frequent contact with humans; therefore, gull-origin H10N7 IAVs could pose a risk to public health. Surveillance and monitoring of these IAVs at the wild bird-human interface should be continued.IMPORTANCE Subtype H10 avian influenza A viruses (IAVs) have caused sporadic human infections and enzootic outbreaks among seals. In the fall of 2015, H10N7 viruses were recovered from gulls in Iceland, and genomic analyses showed that the viruses were genetically related with IAVs that caused outbreaks among seals in Europe a year earlier. These gull-origin viruses showed high binding affinity to human-like glycan receptors. Transmission studies in ferrets demonstrated that the gull-origin IAV could infect ferrets, and that the virus could be transmitted between ferrets through direct contact and aerosol droplets. This study demonstrated that avian H10 IAV can infect mammals and be transmitted among them without adaptation. Thus, avian H10 IAV is a candidate for influenza pandemic preparedness and should be monitored in wildlife and at the animal-human interface.
Collapse
Affiliation(s)
- Minhui Guan
- Department of Basic Science, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi, USA
| | - Jeffrey S Hall
- United States Geological Survey National Wildlife Health Center, Madison, Wisconsin, USA
| | - Xiaojian Zhang
- Department of Basic Science, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi, USA
| | - Robert J Dusek
- United States Geological Survey National Wildlife Health Center, Madison, Wisconsin, USA
| | - Alicia K Olivier
- Department of Population and Pathobiology Medicine, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi, USA
| | - Liyuan Liu
- Department of Basic Science, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi, USA
| | - Lei Li
- Department of Basic Science, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi, USA
| | - Scott Krauss
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Angela Danner
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Tao Li
- Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Wiriya Rutvisuttinunt
- Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Xiaoxu Lin
- Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | | | | | | | - Josh TeSlaa
- United States Geological Survey National Wildlife Health Center, Madison, Wisconsin, USA
| | - Sean W Nashold
- United States Geological Survey National Wildlife Health Center, Madison, Wisconsin, USA
| | - Richard Jarman
- Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Xiu-Feng Wan
- Department of Basic Science, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi, USA
| |
Collapse
|
5
|
Park S, Park JY, Song Y, How SH, Jung K. Emerging respiratory infections threatening public health in the Asia-Pacific region: A position paper of the Asian Pacific Society of Respirology. Respirology 2019; 24:590-597. [PMID: 30985968 PMCID: PMC7169191 DOI: 10.1111/resp.13558] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 02/12/2019] [Accepted: 03/21/2019] [Indexed: 12/28/2022]
Abstract
In past decades, we have seen several epidemics of respiratory infections from newly emerging viruses, most of which originated in animals. These emerging infections, including severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV) and the pandemic influenza A(H1N1) and avian influenza (AI) viruses, have seriously threatened global health and the economy. In particular, MERS-CoV and AI A(H7N9) are still causing infections in several areas, and some clustering of cases of A(H5N1) and A(H7N9) may imply future possible pandemics. Additionally, given the inappropriate use of antibiotics and international travel, the spread of carbapenem-resistant Gram-negative bacteria is also a significant concern. These infections with epidemic or pandemic potential present a persistent threat to public health and a huge burden on healthcare services in the Asia-Pacific region. Therefore, to enable efficient infection prevention and control, more effective international surveillance and collaboration systems, in the context of the 'One Health' approach, are necessary.
Collapse
Affiliation(s)
- Sunghoon Park
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal MedicineHallym University Sacred Heart HospitalAnyangRepublic of Korea
| | - Ji Young Park
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal MedicineHallym University Sacred Heart HospitalAnyangRepublic of Korea
| | - Yuanlin Song
- Department of Pulmonary and Critical Care MedicineZhongshan Hospital, Fudan UniversityShanghaiChina
| | - Soon Hin How
- Department of Internal Medicine, Kulliyyah of MedicineInternational Islamic University MalaysiaKuantanMalaysia
| | - Ki‐Suck Jung
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal MedicineHallym University Sacred Heart HospitalAnyangRepublic of Korea
| | | |
Collapse
|
6
|
Henning J, Hesterberg UW, Zenal F, Schoonman L, Brum E, McGrane J. Risk factors for H5 avian influenza virus prevalence on urban live bird markets in Jakarta, Indonesia-Evaluation of long-term environmental surveillance data. PLoS One 2019; 14:e0216984. [PMID: 31125350 PMCID: PMC6534305 DOI: 10.1371/journal.pone.0216984] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 05/02/2019] [Indexed: 11/19/2022] Open
Abstract
In the re-emergence of Highly Pathogenic Avian Influenza (HPAI), live bird markets have been identified to play a critical role. In this repeated cross-sectional study, we combined surveillance data collected monthly on Jakarta's live bird markets over a five-year period, with risk factors related to the structure and management of live bird markets, the trading and slaughtering of birds at these markets, and environmental and demographic conditions in the areas where the markets were located. Over the study period 36.7% (95% CI: 35.1, 38.3) of samples (N = 1315) tested HPAI H5 virus positive. Using General Estimation Equation approaches to account for repeated observations over time, we explored the association between HPAI H5 virus prevalence and potential risk factors. Markets where only live birds and carcasses were sold, but no slaughtering was conducted at or at the vicinity of the markets, had a significantly reduced chance of being positive for H5 virus (OR = 0.2, 95% CI 0.1-0.5). Also, markets, that used display tables for poultry carcasses made from wood, had reduced odds of being H5 virus positive (OR = 0.7, 95% CI 0.5-1.0), while having at least one duck sample included in the pool of samples collected at the market increased the chance of being H5 virus positive (OR = 5.7, 95% CI 3.6-9.2). Markets where parent stock was traded, were more at risk of being H5 virus positive compared to markets where broilers were traded. Finally, the human population density in the district, the average distance between markets and origins of poultry sold at markets and the total rainfall per month were all positively associated with higher H5 virus prevalence. In summary, our results highlight that a combination of factors related to trading and marketing processes and environmental pressures need to be considered to reduce H5 virus infection risk for customers at urban live bird markets. In particular, the relocation of slaughter areas to well-managed separate locations should be considered.
Collapse
Affiliation(s)
- Joerg Henning
- School of Veterinary Science, University of Queensland, Gatton, Queensland, Australia
| | - Uta Walburga Hesterberg
- Emergency Centre for Transboundary Animal Diseases (ECTAD), Food and Agriculture Organization of the United Nations (FAO), Jakarta, Java, Indonesia
- Emergency Centre for Transboundary Animal Diseases (ECTAD), Food and Agriculture Organization of the United Nations (FAO), Dhaka, Bangladesh
| | - Farida Zenal
- Emergency Centre for Transboundary Animal Diseases (ECTAD), Food and Agriculture Organization of the United Nations (FAO), Jakarta, Java, Indonesia
| | - Luuk Schoonman
- Emergency Centre for Transboundary Animal Diseases (ECTAD), Food and Agriculture Organization of the United Nations (FAO), Jakarta, Java, Indonesia
| | - Eric Brum
- Emergency Centre for Transboundary Animal Diseases (ECTAD), Food and Agriculture Organization of the United Nations (FAO), Jakarta, Java, Indonesia
- Emergency Centre for Transboundary Animal Diseases (ECTAD), Food and Agriculture Organization of the United Nations (FAO), Dhaka, Bangladesh
| | - James McGrane
- Emergency Centre for Transboundary Animal Diseases (ECTAD), Food and Agriculture Organization of the United Nations (FAO), Jakarta, Java, Indonesia
| |
Collapse
|
7
|
Wu H, Yang F, Liu F, Peng X, Chen B, Cheng L, Lu X, Yao H, Wu N. Molecular characterization of H10 subtype avian influenza viruses isolated from poultry in Eastern China. Arch Virol 2018; 164:159-179. [PMID: 30302582 DOI: 10.1007/s00705-018-4019-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 07/25/2018] [Indexed: 02/06/2023]
Abstract
In recent years, avian-origin H10 influenza viruses have proved capable of infecting human beings, and they pose a potential public health threat. Seven H10 avian influenza viruses (AIVs), H10N3 (n = 2), H10N7 (n = 1), and H10N8 (n = 4), were isolated from chickens in Zhejiang Province, Eastern China, during surveillance of AIVs in live poultry markets in 2016 and 2017. Phylogenetic analysis indicated that Zhejiang H10 strains received gene segments from H10, H3, and H7 viruses from birds in East Asia. Animal inoculation tests showed that these isolates have low pathogenicity in mice and can replicate in this species. Our findings suggest these H10 AIVs have the ability to adapt to chicken or other poultry, and highlight the need of long-term surveillance.
Collapse
Affiliation(s)
- Haibo Wu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital School of Medicine, Zhejiang University, Hangzhou, China.
| | - Fan Yang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital School of Medicine, Zhejiang University, Hangzhou, China
| | - Fumin Liu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiuming Peng
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital School of Medicine, Zhejiang University, Hangzhou, China
| | - Bin Chen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital School of Medicine, Zhejiang University, Hangzhou, China
| | - Linfang Cheng
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiangyun Lu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital School of Medicine, Zhejiang University, Hangzhou, China
| | - Hangping Yao
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital School of Medicine, Zhejiang University, Hangzhou, China
| | - Nanping Wu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital School of Medicine, Zhejiang University, Hangzhou, China.
| |
Collapse
|
8
|
Genetic Evidence Supports Sporadic and Independent Introductions of Subtype H5 Low-Pathogenic Avian Influenza A Viruses from Wild Birds to Domestic Poultry in North America. J Virol 2018; 92:JVI.00913-18. [PMID: 30045988 DOI: 10.1128/jvi.00913-18] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 07/04/2018] [Indexed: 11/20/2022] Open
Abstract
Wild-bird origin influenza A viruses (IAVs or avian influenza) have led to sporadic outbreaks among domestic poultry in the United States and Canada, resulting in economic losses through the implementation of costly containment practices and destruction of birds. We used evolutionary analyses of virus sequence data to determine that 78 H5 low-pathogenic avian influenza viruses (LPAIVs) isolated from domestic poultry in the United States and Canada during 2001 to 2017 resulted from 18 independent virus introductions from wild birds. Within the wild-bird reservoir, the hemagglutinin gene segments of H5 LPAIVs exist primarily as two cocirculating genetic sublineages, and our findings suggest that the H5 gene segments flow within each migratory bird flyway and among adjacent flyways, with limited exchange between the nonadjacent Atlantic and Pacific Flyways. Phylogeographic analyses provided evidence that IAVs from dabbling ducks and swans/geese contributed to the emergence of viruses among domestic poultry. H5 LPAIVs isolated from commercial farm poultry (i.e., turkey) that were descended from a single introduction typically remained a single genotype, whereas those from live-bird markets sometimes led to multiple genotypes, reflecting the potential for reassortment with other IAVs circulating within live-bird markets. H5 LPAIVs introduced from wild birds to domestic poultry represent economic threats to the U.S. poultry industry, and our data suggest that such introductions have been sporadic, controlled effectively through production monitoring and a stamping-out policy, and are, therefore, unlikely to result in sustained detections in commercial poultry operations.IMPORTANCE Integration of viral genome sequencing into influenza surveillance for wild birds and domestic poultry can elucidate evolutionary pathways of economically costly poultry pathogens. Evolutionary analyses of H5 LPAIVs detected in domestic poultry in the United States and Canada during 2001 to 2017 suggest that these viruses originated from repeated introductions of IAVs from wild birds, followed by various degrees of reassortment. Reassortment was observed where biosecurity was low and where opportunities for more than one virus to circulate existed (e.g., congregations of birds from different premises, such as live-bird markets). None of the H5 lineages identified were maintained for the long term in domestic poultry, suggesting that management strategies have been effective in minimizing the impacts of virus introductions on U.S. poultry production.
Collapse
|
9
|
Simultaneous detection of eight avian influenza A virus subtypes by multiplex reverse transcription-PCR using a GeXP analyser. Sci Rep 2018; 8:6183. [PMID: 29670227 PMCID: PMC5906657 DOI: 10.1038/s41598-018-24620-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 04/03/2018] [Indexed: 01/16/2023] Open
Abstract
Recent studies have demonstrated that at least eight subtypes of avian influenza virus (AIV) can infect humans, including H1, H2, H3, H5, H6, H7, H9 and H10. A GeXP analyser-based multiplex reverse transcription (RT)-PCR (GeXP-multiplex RT-PCR) assay was developed in our recent studies to simultaneously detect these eight AIV subtypes using the haemagglutinin (HA) gene. The assay consists of chimeric primer-based PCR amplification with fluorescent labelling and capillary electrophoresis separation. RNA was extracted from chick embryo allantoic fluid or liquid cultures of viral isolates. In addition, RNA synthesised via in vitro transcription was used to determine the specificity and sensitivity of the assay. After selecting the primer pairs, their concentrations and GeXP-multiplex RT-PCR conditions were optimised. The established GeXP-multiplex RT-PCR assay can detect as few as 100 copies of premixed RNA templates. In the present study, 120 clinical specimens collected from domestic poultry at live bird markets and from wild birds were used to evaluate the performance of the assay. The GeXP-multiplex RT-PCR assay specificity was the same as that of conventional RT-PCR. Thus, the GeXP-multiplex RT-PCR assay is a rapid and relatively high-throughput method for detecting and identifying eight AIV subtypes that may infect humans.
Collapse
|
10
|
Agunos A, Pierson FW, Lungu B, Dunn PA, Tablante N. Review of Nonfoodborne Zoonotic and Potentially Zoonotic Poultry Diseases. Avian Dis 2017; 60:553-75. [PMID: 27610715 DOI: 10.1637/11413-032416-review.1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Emerging and re-emerging diseases are continuously diagnosed in poultry species. A few of these diseases are known to cross the species barrier, thus posing a public health risk and an economic burden. We identified and synthesized global evidence for poultry nonfoodborne zoonoses to better understand these diseases in people who were exposed to different poultry-related characteristics (e.g., occupational or nonoccupational, operational types, poultry species, outbreak conditions, health status of flocks). This review builds on current knowledge on poultry zoonoses/potentially zoonotic agents transmitted via the nonfoodborne route. It also identifies research gaps and potential intervention points within the poultry industry to reduce zoonotic transmission by using various knowledge synthesis tools such as systematic review (SR) and qualitative (descriptive) and quantitative synthesis methods (i.e., meta-analysis). Overall, 1663 abstracts were screened and 156 relevant articles were selected for further review. Full articles (in English) were retrieved and critically appraised using routine SR methods. In total, eight known zoonotic diseases were reviewed: avian influenza (AI) virus (n = 85 articles), Newcastle disease virus (n = 8), West Nile virus (WNV, n = 2), avian Chlamydia (n = 24), Erysipelothrix rhusiopathiae (n = 3), methicillin-resistant Staphylococcus aureus (MRSA, n = 15), Ornithonyssus sylvarium (n = 4), and Microsporum gallinae (n = 3). In addition, articles on other viral poultry pathogens (n = 5) and poultry respiratory allergens derived from mites and fungi (n = 7) were reviewed. The level of investigations (e.g., exposure history, risk factor, clinical disease in epidemiologically linked poultry, molecular studies) to establish zoonotic linkages varied across disease agents and across studies. Based on the multiple outcome measures captured in this review, AI virus seems to be the poultry zoonotic pathogen that may have considerable and significant public health consequences; however, epidemiologic reports have only documented severe human cases clustered in Asia and not in North America. In contrast, avian Chlamydia and MRSA reports clustered mainly in Europe and less so in North America and other regions. Knowledge gaps in other zoonoses or other agents were identified, including potential direct (i.e., nonmosquito-borne) transmission of WNV from flocks to poultry workers, the public health and clinical significance of poultry-derived (livestock-associated) MRSA, the zoonotic significance of other viruses, and the role of poultry allergens in the pathophysiology of respiratory diseases of poultry workers. Across all pathogens reviewed, the use of personal protective equipment was commonly cited as the most important preventive measure to reduce the zoonotic spread of these diseases and the use of biosecurity measures to reduce horizontal transmission in flock populations. The studies also emphasized the need for flock monitoring and an integrated approach to prevention (i.e., veterinary-public health coordination with regard to diagnosis, and knowledge translation and education in the general population) to reduce zoonotic transmission.
Collapse
Affiliation(s)
- Agnes Agunos
- A Public Health Agency of Canada, Guelph, Ontario, Canada N1G5B2
| | - F William Pierson
- B Department of Population Health Sciences, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | - Bwalya Lungu
- C Department of Food Science and Technology, University of California, Davis, CA 95616
| | - Patricia A Dunn
- D Animal Diagnostic Laboratory (PADLS-PSU), Pennsylvania State University, University Park, PA 16802
| | - Nathaniel Tablante
- E Virginia-Maryland College of Veterinary Medicine, University of Maryland, College Park, MD 20740
| |
Collapse
|
11
|
A quantitative RT-PCR assay for rapid detection of Eurasian-lineage H10 subtype influenza A virus. Virol Sin 2017; 31:444-447. [PMID: 27699612 DOI: 10.1007/s12250-016-3826-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
|
12
|
Zhu H, Lam TTY, Smith DK, Guan Y. Emergence and development of H7N9 influenza viruses in China. Curr Opin Virol 2016; 16:106-113. [PMID: 26922715 DOI: 10.1016/j.coviro.2016.01.020] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 01/27/2016] [Indexed: 02/05/2023]
Abstract
The occurrence of human infections with avian H7N9 viruses since 2013 demonstrates the continuing pandemic threat posed by the current influenza ecosystem in China. Influenza surveillance and phylogenetic analyses showed that these viruses were generated by multiple interspecies transmissions and reassortments among the viruses resident in domestic ducks and the H9N2 viruses enzootic in chickens. A large population of domestic ducks hosting diverse influenza viruses provided the precondition for these events to occur, while acquiring internal genes from enzootic H9N2 influenza viruses in chickens promoted the spread of these viruses. Human infections effectively act as sentinels, reflecting the intensity of the activity of these viruses in poultry.
Collapse
Affiliation(s)
- Huachen Zhu
- Joint Influenza Research Centre (SUMC/HKU), Shantou University Medical College, Shantou 515041, China; State Key Laboratory of Emerging Infectious Diseases (HKU-Shenzhen Branch), Shenzhen Third People's Hospital, Shenzhen 518112, China; Centre of Influenza Research, School of Public Health, The University of Hong Kong, Hong Kong, China.
| | - Tommy Tsan-Yuk Lam
- Centre of Influenza Research, School of Public Health, The University of Hong Kong, Hong Kong, China
| | - David Keith Smith
- Centre of Influenza Research, School of Public Health, The University of Hong Kong, Hong Kong, China
| | - Yi Guan
- Joint Influenza Research Centre (SUMC/HKU), Shantou University Medical College, Shantou 515041, China; State Key Laboratory of Emerging Infectious Diseases (HKU-Shenzhen Branch), Shenzhen Third People's Hospital, Shenzhen 518112, China; Centre of Influenza Research, School of Public Health, The University of Hong Kong, Hong Kong, China
| |
Collapse
|
13
|
Xiao C, Ma W, Sun N, Huang L, Li Y, Zeng Z, Wen Y, Zhang Z, Li H, Li Q, Yu Y, Zheng Y, Liu S, Hu P, Zhang X, Ning Z, Qi W, Liao M. PB2-588 V promotes the mammalian adaptation of H10N8, H7N9 and H9N2 avian influenza viruses. Sci Rep 2016; 6:19474. [PMID: 26782141 PMCID: PMC4726052 DOI: 10.1038/srep19474] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 12/01/2015] [Indexed: 12/20/2022] Open
Abstract
Human infections with avian influenza H7N9 or H10N8 viruses have been reported in China, raising concerns that they might cause human epidemics and pandemics. However, how these viruses adapt to mammalian hosts is unclear. Here we show that besides the commonly recognized viral polymerase subunit PB2 residue 627 K, other residues including 87E, 292 V, 340 K, 588 V, 648 V, and 676 M in PB2 also play critical roles in mammalian adaptation of the H10N8 virus. The avian-origin H10N8, H7N9, and H9N2 viruses harboring PB2-588 V exhibited higher polymerase activity, more efficient replication in mammalian and avian cells, and higher virulence in mice when compared to viruses with PB2-588 A. Analyses of available PB2 sequences showed that the proportion of avian H9N2 or human H7N9 influenza isolates bearing PB2-588 V has increased significantly since 2013. Taken together, our results suggest that the substitution PB2-A588V may be a new strategy for an avian influenza virus to adapt mammalian hosts.
Collapse
Affiliation(s)
- Chencheng Xiao
- National and Local Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, People's Republic of China
| | - Wenjun Ma
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS 66502, USA
| | - Na Sun
- National and Local Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, People's Republic of China
| | - Lihong Huang
- National and Local Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, People's Republic of China
| | - Yaling Li
- National and Local Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, People's Republic of China
| | - Zhaoyong Zeng
- National and Local Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, People's Republic of China
| | - Yijun Wen
- National and Local Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, People's Republic of China
| | - Zaoyue Zhang
- National and Local Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, People's Republic of China
| | - Huanan Li
- National and Local Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, People's Republic of China
| | - Qian Li
- National and Local Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, People's Republic of China
| | - Yuandi Yu
- National and Local Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, People's Republic of China
| | - Yi Zheng
- National and Local Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, People's Republic of China
| | - Shukai Liu
- National and Local Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, People's Republic of China
| | - Pingsheng Hu
- National and Local Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, People's Republic of China
| | - Xu Zhang
- National and Local Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, People's Republic of China
| | - Zhangyong Ning
- National and Local Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, People's Republic of China
| | - Wenbao Qi
- National and Local Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, People's Republic of China
| | - Ming Liao
- National and Local Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, People's Republic of China
| |
Collapse
|
14
|
Su W, Wang C, Luo J, Zhao Y, Wu Y, Chen L, Zhao N, Li M, Xing C, Liu H, Zhang H, Chang YF, Li T, Ding H, Wan X, He H. Testing the Effect of Internal Genes Derived from a Wild-Bird-Origin H9N2 Influenza A Virus on the Pathogenicity of an A/H7N9 Virus. Cell Rep 2015; 12:1831-41. [PMID: 26344762 DOI: 10.1016/j.celrep.2015.08.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 06/24/2015] [Accepted: 08/07/2015] [Indexed: 01/11/2023] Open
Abstract
Since 2013, avian influenza A(H7N9) viruses have diversified into multiple lineages by dynamically reassorting with other viruses, especially H9N2, in Chinese poultry. Despite concerns about the pandemic threat posed by H7N9 viruses, little is known about the biological properties of H7N9 viruses that may recruit internal genes from genetically distinct H9N2 viruses circulating among wild birds. Here, we generated 63 H7N9 reassortants derived from an avian H7N9 and a wild-bird-origin H9N2 virus. Compared with the wild-type parent, 25/63 reassortants had increased pathogenicity in mice. A reassortant containing PB1 of the H9N2 virus was highly lethal to mice and chickens but was not transmissible to guinea pigs by airborne routes; however, three substitutions associated with adaptation to mammals conferred airborne transmission to the virus. The emergence of the H7N9-pandemic reassortant virus highlights that continuous monitoring of H7N9 viruses is needed, especially at the domestic poultry/wild bird interface.
Collapse
Affiliation(s)
- Wen Su
- National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of the Chinese Academy of Sciences, Beijing 100101, China
| | - Chengmin Wang
- National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jing Luo
- National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yuliang Zhao
- National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yan Wu
- Department of Infectious Diseases, Hangzhou Center for Disease Control and Prevention, Hangzhou, Zhejiang 310021, China
| | - Lin Chen
- National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of the Chinese Academy of Sciences, Beijing 100101, China
| | - Na Zhao
- National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of the Chinese Academy of Sciences, Beijing 100101, China
| | - Meng Li
- National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of the Chinese Academy of Sciences, Beijing 100101, China
| | - Chao Xing
- National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Huimin Liu
- National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Hong Zhang
- National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yung-fu Chang
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University Ithaca, NY 14853-5786, USA
| | - Tianxian Li
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071, China
| | - Hua Ding
- Department of Infectious Diseases, Hangzhou Center for Disease Control and Prevention, Hangzhou, Zhejiang 310021, China
| | - Xiufeng Wan
- Department of Basic Sciences, College of Veterinary Medicine, and Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA
| | - Hongxuan He
- National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
| |
Collapse
|
15
|
Sun L, Wang L, Zhang W, Sun Y, Luo Y, Sun Y, Yuan Z, Wang H, Ning Z, Jia K, Yuan LG. Lack of exposure of H10N8 avian influenza virus among veterinarians in Guangdong Province, China. J Med Virol 2015; 87:2018-20. [PMID: 25980313 DOI: 10.1002/jmv.24268] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/10/2015] [Indexed: 11/10/2022]
Abstract
We conducted a retrospective seroepidemiological study for H10N8 avian influenza infection among 400 veterinarians sampled from February 2013 to August 2013 in Guangdong Province, China. None of the veterinarians had evidence of previous infection with the emergent H10N8 AIV. Although there is no evidence of H10N8-infected veterinarian before the first human index case of H10N8 infection in southern China, a more rigorous and long-term surveillance remained essential for early warning of novel reassortant viruses and interspecies transmission events.
Collapse
Affiliation(s)
- Lingshuang Sun
- College of Veterinary Medicine, South China Agricultural University, Guangdong Province 510642, People's Republic of China.,Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangdong Province 510642, People's Republic of China
| | - Lifang Wang
- College of Veterinary Medicine, South China Agricultural University, Guangdong Province 510642, People's Republic of China
| | - Weidong Zhang
- Hospital of South China Agricultural University, Guangzhou 510642, China
| | - Yankuo Sun
- College of Veterinary Medicine, South China Agricultural University, Guangdong Province 510642, People's Republic of China
| | - Yongfeng Luo
- College of Veterinary Medicine, South China Agricultural University, Guangdong Province 510642, People's Republic of China
| | - Yao Sun
- College of Veterinary Medicine, South China Agricultural University, Guangdong Province 510642, People's Republic of China
| | - Ziguo Yuan
- College of Veterinary Medicine, South China Agricultural University, Guangdong Province 510642, People's Republic of China.,Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangdong Province 510642, People's Republic of China
| | - Heng Wang
- College of Veterinary Medicine, South China Agricultural University, Guangdong Province 510642, People's Republic of China.,Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangdong Province 510642, People's Republic of China
| | - Zhangyong Ning
- College of Veterinary Medicine, South China Agricultural University, Guangdong Province 510642, People's Republic of China.,Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangdong Province 510642, People's Republic of China
| | - Kun Jia
- College of Veterinary Medicine, South China Agricultural University, Guangdong Province 510642, People's Republic of China.,Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangdong Province 510642, People's Republic of China
| | - Li-Guo Yuan
- College of Veterinary Medicine, South China Agricultural University, Guangdong Province 510642, People's Republic of China.,Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangdong Province 510642, People's Republic of China
| |
Collapse
|